Space Heating.

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Presentation on theme: "Space Heating."— Presentation transcript:

2 Heating in RdSAP RdSAP allows you to include:A main heating system (e.g. boiler)An additional main heating system, (2nd main system)A secondary heater (room heater)The additional heating system allows two main heating systems to be included in the EPC. This means a wider variety of heating setups can be specified in RdSAP.The secondary heating must be based on fixed room heaters e.g. gas/ solid fuel fires, electric heatersit is not possible to select a central heating system as secondary heating.

3 Main heating The main heating system is defined as:A system which heats the largest proportion of the dwellingA system which is not usually based on individual room heaters (although it can be)A system which usually also provides the water heatingA typical main heating system would be a central heating boilerIf there is more than one heating system or device in a property use the following process to decide which is the main heating systemThe main system usually provides both space and water heating and should heat at least 30% of the dwellingIf no system provides space and water heating then select the system which heats the greatest part of the dwellingIf there is still doubt then select the system which supplies useful heat to the dwelling at the lowest costIf the costs are the same then select the system which heats the living room

4 Additional main systemIf a dwelling has an additional main system then the proportion of the property heated by each system should be calculated. This should be based on heated floor area to the nearest 10%If two systems serve the same heating circuit then assume there is a 50/50 splitThe main system should be the one which heats the living areaExamples where an additional main system can be usedA large property has two different boilers fitted so the whole property can be heated. One boiler is the main system the other is the additional main system.A property has a boiler fitted to replace storage heaters, but some functioning storage heaters are left in the property, the boiler is the main system and the storage heaters are the additional systemPreviously only one main heating system could be entered, which restricted RdSAP and meant some properties could not be accurately modelled.

5 Secondary heatingSecondary heating must be based on fixed room heaters.A fixed room heater is an independent heater not on a central system, such as a gas fire or electric panel heater. The heater must be fixed in place, so portable heaters are not included in the assessment.This means it is only possible to select the followingOil room heatersElectric room heatersSolid fuel room heatersGas room heatersIf there is more than one secondary heater in a property then use the following process to identify the heater which should be selected:Select the type of heater which heats the greatest number of habitable roomsIf that does not resolve the choice then select the heater which is cheapest to run, based on fuel costIf that still does not narrow it down, select the device with the lowest efficiency

6 Secondary heatingPortable heaters can be specified in particular circumstances:When the main heating system is an off-peak storage system (this is covered later in this section) and no other type of secondary heating is presentThe software will automatically include portable heaters in the EPC in particular circumstances:If the main heating system is not deemed sufficient to heat a dwelling, and no secondary heating is specified.If there is no heating system present in the dwelling at allPortable heaters are defined asCompletely free-standing and self-supportingContains a built in fuel store, or for electric heaters, has a lead and plugCan be easily moved between roomsFocal point electric fires designed for the located in a fireplace can be included in the assessment as a fixed heater

8 Types of boilerThe most common type of boiler you will encounter will be Mains Gas as is it the most widely available fuel.The boilers will eitherRegular boilerBack boilerCombi boilerCondensing boilerCombined Primary Storage Unit

10 Regular Boiler Key features of a regular boilerIt can provide heating and hot water for a dwellingThe hot water must be stored in a cylinderThere are usually 3 pipes coming out of a regular boiler, gas supply, flow and return)The boiler heats water which then flows around the heating system and to the hot water tankGenerally have 3 pipes, can’t always see all of themGas supplyFlow pipe from boiler to heating systemReturn pipe, from heating system to boiler

11 Back BoilerA back boiler is a type of regular boiler, these are fitted behind a fire.It provides space heating and hot water.As with a regular boiler the water is stored in a cylinder.What is a back boiler?Room heater- gas, coal, wood etc, heat from fire heats water in back boilerOld method of heating water for hot water and heatingSome modern back boilers

12 Back Boilers Back boilers can be Gas, solid fuel OilIn RdSAP gas and solid fuel back boilers can be identified as central heating systemsGas and solid fuel back boilers are sometimes listed in the PCDF but not always

13 Identifying a back boilerHow can you tell if a gas fire has a back boiler?Look for a plate at the bottom of the fire, this may come away to reveal the boiler controlsBack boilers are usually more substantial than a normal gas fireThere will usually be a control dial, sometimes with the boiler name on itThere may be a cylinder with no boiler unit

15 Combi BoilerA combi or combination boiler provides heating in the same way a regular boiler doesIt provides domestic hot water on demand, rather than storing it in a cylinder.A combi boiler is easily identified as it usually has 5, 6 or 7 pipes.Combi boilers also have more controls on the front of them e.g. heating, hot water and sometime a programmer

18 Condensing BoilerA condensing boiler is a highly efficient type of boilerMost non-condensing boilers emit hot combustion gases, but a condensing boiler extracts the heat from the combustion gases before they are emitted, pre-warming the water in the boiler.This means the flue gases emitted are a lower temperatureThere is some condensation of flue gases as they leave the boiler, these are drained out of the boiler through a plastic condensate pipe. This is the key identifying feature of most condensing boilersBecause the flue gases are cooler a plastic flue can be used, rather than a metal flueOn a cold day you may be able to see a plume of water vapour coming from the flue.

20 Condensing BoilerCombustion gases pass over the primary heat exchanger and are then directed over the secondary heat exchanger.As the gases condense on the sides of the exchanger they release heatThe condensate is drained via a plastic pipe – this is often the easiest way to identify a condensing boiler, visible at bottom of boiler and on external wallThe exhaust gases from the flue are at a much lower temp than a conventional boiler due to the extra heat being taken from them. On a cold day you can see a plume of water vapour coming from the flueDue to lower temp of flue gases the flue itself can be made of plastic

22 Combined Primary Storage UnitThis is an appliance which incorporates the provision of space heating and hot water; the hot water store should be at least 70L and integral to the appliance.This type of appliance is usually floor mounted and larger than a conventional boiler

23 Underfloor HeatingUnderfloor heating can be fitted to a boiler if it is fitted there will be a manifold such as the one pictured.This manifold distributes the hot water amongst the underfloor heating loopsIf both underfloor heating and radiators are present in a property it is not possible to include both as the heat emitter. Radiators should be specified as they require a higher flow temperature, making them the worst case scenario

27 PCDF Product Characteristic Data FileThe PCDF is a searchable database which includes the following types of heating systemsGas and oil boilersMicroCHP*Heat Pumps *Solid fuel boilers *The PCDF contains specific technical details about heating devices, including their seasonal efficiencyRdSAP software incorporates the PCDF when searching for heating systems* Covered later in this section

28 PCDFMake sure you collect the device make and model information so you can accurately identify it in the PCDF.If a device cannot be found in the PCDF then there is a list of types of heating systems in RdSAP, the device should be selected from this generic list, known as the alternative method in Stroma’s software.

29 Boiler ID PlateVery useful to get enough detail for SEDBUK searchThe boiler ID plate is a very useful way of finding out all the information needed to find the specific boiler in the PCDF

31 Open FlueOpen flues are usually found with older, floor mounted boilersThe combustion gases are taken from within the room the boiler is in.The combustion gases are drawn up from the boiler by wind passing over the top of the flueOlder boilers- often oil boilers and floor mounted gas boilers have open flue

32 Open FlueThis is the more common type of open flue, these are found on the top of converted chimneys.

33 Open Flue Draws air from the room for combustion.Flue products naturally rise upwards, through chimney or vent

34 Balanced FlueThis type of flue uses air from outside the dwelling for combustion.It relies on natural air movement to draw the hot air back outside from the boilerThe flue must be located as close to the boiler as possible to keep the flue length shortA balanced flue is classed as ‘room sealed’Older gas, wall mounted boilersAlso called biscuit tin due to size and shape

36 Fan assisted flueThis is a room sealed flue which uses a fan to assist the movement of the air through the flueThis means the flue doesn’t have to rely on natural air movement and can be located further from the boiler

37 Fanned Flue for Regular BoilerAir drawn in from outside, unlike open flueBoilers with balanced flue most be located next to the external wall

39 Flue Gas Heat RecoveryFlue Gas Heat Recovery Systems (FGHRS) are designed to recover heat in the flue gases discharged from a condensing boiler.The boiler can be fired by natural gas, LPG or oil.They use the cold temperature of the domestic cold water supply to recover extra heat that is not extracted by the boiler.This recovered heat is used to heat the hot water supply in two principle ways:Instantly – Recovered heat is immediately used to pre-heat to the domestic water supply before it enters the boiler or external hot water cylinder.Deferred – Heat recovered during space heating production is stored for later use to pre-heat the domestic water supply before it enters the boiler or external hot water cylinder the next time hot water is required

40 Flue Gas Heat RecoveryFGHRS can either be integral to the boiler or separate from the boiler.An integral system is known as a Passive Flue Gas Heat Recovery Device (PFGHRD), and selecting the correct boiler from the PCDF database will include the heat recovery system in the calculationFGHRS can be fitted to existing boilers, in which case the system will be separate from the boilerThe FGHRS should be visible above the boiler, where the flue outlet is located.In order to include the FGHRS it must be in the PCDF

41 Flue Gas heat RecoveryA flue gas heat recovery system will normally be found just above the boiler unit.Remember that the system must be included in the database in order to be included in the assessment

43 Flue Gas Heat RecoveryRecord the standard PV data, kWp, tilt, orientation and overshadingA FGHRS can be fitted to a separate hot water storeIf this is the case it may be powered by PVMake sure you check for a solar PV array installed specifically to power the FGHRSThere is a section in the software for FGHRS and a PV array specific to it

44 Flue Gas Heat Recovery RdSAP Convention 9.06 states:Include [FGHRS] only if found in database, identified in same way as for heating systems. When the model cannot be found no default option is available but the presence of the device should be recorded in site notes

46 Electric Central HeatingThis is an electric direct acting boilerThe unit is about 1metre long and can provide heating and hot water, if a cylinder is fittedCommon examples of this type of boiler are the Heatrae Sadia Amptec and the Trianco Aztec Classis

47 Electric central heatingThis is an electric water storage boilerIt uses cheap rate electricity over night to heat water for space and water heatingThere is a water cylinder within the unitThe cylinder must be less than 270L, if it is bigger the device is classed as a Electric CPSU

48 Electric central heatingElectric CPSU – like a gas CPSU this device has a hot water tank within the deviceThe water store must be over 270L for it to be classed as a CPSU, otherwise it is an Electric water storage boilerThese units are generally quite large, around 1.8m tall so will be found in cupboards.Electric CPSU

49 Electric central heatingElectric dry core storage boiler ; this works in a similar way to storage heaters, using cheap rate electricity to heat bricks inside the unitThe heat is transferred from the bricks to water via a heat exchanger to provide space and water heating

50 Solid Fuel Boiler These can be either manual or auto (gravity) feedSolid fuel boilers run on traditional solid fuels such as anthracite, or they can run on biofuels such as wood pelletsSolid fuel boilers are usually regular boilers capable of providing heating and hot water for a property.Auto feed, solid fuel boilerFill hopper with solid fuel (coal, anthracite, pellets)

51 Range CookersAga, RayburnCan provide heating and hot waterVery inefficient in RDSAPTo be accounted for as a heating system a range cooker must incorporate a boiler capable of providing space heatingRange cookers can run on solid fuel, gas or oil

52 Range Cookers Gas and oil range cookers can either beTwin burner – has two burners one for heating and one for cookingSingle burner – one burner which does heating and cookingIf the range cooker is just supplying hot water it can be specified in the RdSAP software. This will be covered in more detail in the water heating section.

53 Warm Air System – Gas FiredWarm air systems blow warm air out of vents located around the propertyThe main unit is floor mounted and about 1.5-2m tallWarm air systems can run on gas, oil or electricityElectric warm air systems use off peak electricity to store heat overnight, so the property should have a dual rate electricity meterPopular in 60s and 70sVery noisy, rattley systemVents located along piping round property which emit warm airAlso available as electric system – electricaire – use off-peak electricity and store up heat overnight.

54 Warm Air – Typical VentExtra care should be taken when looking for the vents, many can be hidden behind wardrobes, sofas etc.

55 Electric Storage HeatersOld style storage heater, very big, floor mountedMake use of off-peak/economy 7 electricity which is sold at a much cheaper rateMake sure you check the electricity meter in properties with storage heatersIt is likely to have a dual immersion on the HWT too- look at this in a bitStorage heaters use cheap rate electricity over night to store up heat in bricks within the heaters. This heat is then released during the dayStorage heaters make use of off-peak/economy 7 electricity which is sold at a much cheaper rateStorage heaters use drift heat, and are often placed in hallways and landings, as well as the main living area

57 Old (large volume) storage heatersOld storage heaters are usually quite large, around 20-25cm deepThey sit directly on the floor due to the weight of the bricks inside the heater

58 Modern Slimline Storage HeaterOften have small feet for support – not solely wall mountedModern storage heaters are narrower, around 10-15cmThey are sometimes attached to the wall with small feel to support their weight

59 Modern Fan Assisted Storage HeaterSome more modern storage heaters are fan assisted to improve the distribution of heat from the device,These heaters have additional vents at the bottom and two separate wires coming from the device, one for the peak rate meter, for the fan, and the other to the off peak meter, for the over-night chargingrequires 2 AC Supplies

60 Integrated storage and direct actingThese storage heaters have a direct acting panel heaters integrated into the device.This means the device is capable of providing on-demand heat as well as the release of stored heat

61 Storage heatingWhen certain types of storage heaters are the main heating a secondary system should be specified.Old (large volume) storage heatersModern (slim line) storage heatersFan storage heatersElectric underfloor – in concrete slabBecause integrated storage heaters and integrated underfloor heating have direct acting heaters included in the device there is no need to specify any secondary heating

62 Electric underfloor heatingIn concrete slab (off-peak)This system uses the floor to store heat, much like storage heaters use the bricksThere should be a dual electricity tariff available to the propertyIn screed above insulation (standard tariff)Cables are laid just under the floor surface and provide on-demand heat.This system uses peal rate electricity and is often installed in one room, usually a bathroom or kitchen)

63 Electric underfloor heatingIntegrated (storage and direct acting)This system combines the off-peak and on-peak systemsTwo sets of cables are laid in the floor, one placed lower than the other to provide the off-peak heating

64 Electric ceiling heatersThis form of heating is very unusual in domestic properties.It was most commonly fitted in the 1970s and 1980s.It works in a similar way to underfloor heating, with panels embedded in the ceiling construction, with insulation fitted above.

65 Heat pumps Heat pumps are becoming increasingly common in the UKThey can be used as part of a wet central heating system or a warm air systemHeat pumps work by extracting heat from a low temperature source and increasing the temperature so it can be used for heating.This results in greater than 100% efficiency as the amount of energy used is less than the heat energy generated

66 Ground Source Heat PumpsA ground source heat pump is a device for converting energy in the form of low level heat to heat at a usable temperature.The heat pump consists of three main parts;- ground collector loop,- compressor,- condenser heat exchanger

68 Ground Source Heat PumpThe ground collector loop can either be laid horizontally or vertically, this is dependent on land available

69 Air Source Heat PumpsOperating in a similar way to Ground Source Heat Pumps, Air Source Heat Pumps are an alternative way of extracting useful thermal energy from the air if ground space is not available.

70 Community heatingCommunity heating is a system which provides heat to more than one dwellingTypically community heating would be available in a block of flatsThe system in place would be a large industrial size boiler system housed in a boiler roomIt is unusual to get access to the boiler room, but the system can usually be identified by the lack of a boiler in the dwelling, but a wet heating system is present.

71 Community heatingThree types of community system are available in RdSAPCommunity boilers only: a standard heating system which can provide space and water heatingCommunity CHP and boilers: a more complex system which includes Combined Heat and Power. You must have evidence this is present to include in the survey. (more details in the next few slides)Community heat pumps – large heat pump system which runs on electricity, often a warm air system with vents visible in the dwelling. Fan-coils can be selected as an emitter for community heat pumps

72 Community heatingTry and determine the fuel type of the community heating system, if this is not possible assume the fuel is Mains gas.Additional fuel types are available to community heating as well as the standard fuels such as mains gas and oilB30D – a form of biofuel made up of 30% bio diesel and 70% oilWaste combustion – heat produced at incinerators and similar waste disposal sites canBiomassBiogas – landfill and sewage gasIf community heating provides hot water only and the space heating comes from an alternative source, such as electric panel heaters, then the community heating can be specified as the water heating.Further details on this are covered in the Water Heating slides.

73 Combined Heat and Power (CHP)Bristol City CouncilCommunity HeatingWhen electricity is generated in central power stations around 60-65% of the primary energy is rejected as waste heat into the atmosphere.Combined heat and power units generate electricity locally so that waste heat can be used for beneficial purposes for heating or hot water.Where all waste heat generated can be used, CHP units will have overall efficiencies of up to 80-85% compared to 35-40% for conventional power stations.

74 Combined Heat and Power SystemsCHP systems produce roughly twice as much waste heat as they generate electricity. To be viable and economic, CHP require a large constant demand for heat.Current insulation standards mean the requirement for space heating is very low and demand is present only part of the year. The only constant source of heat demand is for domestic hot water and in terms of reducing CO2 emissions some of the demand could be met by the use of solar water heating instead.For large CHP systems to be economically viable they need to run for at least 4,000 hours per year. They are most suited to leisure centres with swimming pools and hospitals

75 MicroCHPMicro Combined Heat and Power units are systems designed on a smaller scale than standard CHPMicro CHP mainly generates heat, with some electricity generationIf the electricity is not used in the home it can be sold back to the grid

76 MicroCHP Most micro CHP systems run on mains gas or LPGThe latest micro CHP devices are similar in size to a domestic boilerSome micro CHP systems are now listed on the PCDF. If they cannot be found on the database they should be listed as a condensing boiler used the alternative method.

77 Room Heaters Gas fired Solid fuel ElectricSecondary HeatingRoom HeatersGas firedSolid fuelElectricThese can be main source of heat in a property, but usually are secondary heat source

78 Secondary HeatingRoom heaters can be specified as the main heating system or a secondary heaterOnly room heaters can be specified as secondary heatersRoom heaters should not be specified as the main system or additional system unless the only heating in the dwelling is from room heatersRoom heaters are not listed in the PCDF, so they have to be entered into the software using the alternative method

79 Gas FiresThere are a range of gas fire options in RdSAP The options available have descriptive titles which can be used to help identify the type of gas fire you have

80 Gas FiresSelecting the correct gas fire is important as the efficiencies vary between the appliancesGas fire, open flue, pre-1980 (open fronted) with or without back boilerGas fire, open flue, 1980 or later (open fronted), sitting proud of and sealed to fireplace opening, with or without back boiler unitFlush fitting live fuel effect gas fire (open fronted), sealed to fireplace opening, with or without back boiler unitFlush fitting live fuel effect gas fire (open fronted), fan-assisted, sealed to fireplace opening.Gas fire or wall heater, balanced flueGas fire, closed fronted, fan assistedCondensing gas fireDecorative fuel effect gas fire, open to chimneyFlueless gas fire, secondary heating only

81 Gas FiresGas fire, open flue, pre-1980 (open fronted) with or without back boilerAn older style of gas fire, often with the ceramic blocks which radiate the heat when lit

82 Gas FiresGas fire, open flue, 1980 or later (open fronted), sitting proud of and sealed to fireplace opening, with or without back boiler unitThis type of gas fire is a bit more modern, it must be sat in front of the fireplace, rather than being built into itOpen fronted in this case means the combustion gases are taken from the room, so the heater is not sealed. There may be a glass panel in front of the coals on this type of appliance, but it does not seal the unit.

83 Gas FiresFlush fitting live fuel effect gas fire (open fronted), sealed to fireplace opening, with or without back boiler unitThis appliance sits in the fireplace, it is usually a single unit which fits in the fireplace and controls the airflow up the chimney

84 Gas Fires Decorative fuel effect gas fire, open to chimneyThis type of gas fire is similar to a flush fitting live fuel effect gas fire, but there is no control of the airflow, so the efficiency of the appliance is quite poor

85 Gas Fires Gas fire or wall heater, balanced flueThis type of appliance will have a balanced flue on the external wall

86 Gas Fires Condensing gas fireShould have a condensate pipe and fanned flueThese types of gas fire are not particularly common, the main manufacturer is Mantis

87 Gas Fires Gas fire, closed fronted, fan assistedthe appliance must be sealed from the roomA glass panel which does not seal off the appliance is not considered a ‘closed fronted’ appliance

88 Gas Fires Flueless gas fire, secondary heating onlyThis is a very efficient type of gas fireThere should be no flue coming from the appliance, so it can be freestanding

89 Oil Room heaters There are less oil room heaters to choose fromRoom heater, pre 2000, with or without back boilerRoom heater, 2000 or later, with or without back boilerBioethanol heater, secondary heating only

90 Oil Room heatersTake care to ensure they use oil, there should be an oil tank present at the propertyThe age of oil room heaters should be based on how old they look

91 Oil room heaters Bioethanol heaterThese appliances must use bioethanol fuelthe bioethanol is in liquid or gel formThey can be freestanding because they do not need a fixed fuel supply or flue

92 Solid Fuel Room HeaterSolid fuel room heaters are generally quite inefficient appliances as the majority of the heat is lost up the chimney or flueThe following options are availableOpen fire in grate with or without back boilerClosed room heater with or without back boilerStove (pellet fired) with or without back boilerUse house coal, smokeless fuel, wood, dual fuelThese appliances can burn a variety of solid fuels, but the exact options are determined by whether or not a property is located in a Smoke Control Zone

96 Electric Heaters There are three types of electric heatersPanel, convector or radiant heaterWater or oil-filled radiatorsPortable electric heatersPortable electric heaters should not be specified unless they are secondary heating to a storage heating systemDo not confuse panel heaters with storage heater

98 Water or oil filled radiatorsThese should be fixed heatersThey look like normal wet radiators but have electrical wires where you would usually see pipe work

99 Portable Portable electric heatingThis type of electric heater should not be fixedThe heater should be self-supporting and have a flex and plugThis type of heater should be ignored unless the dwelling has electric storage heating

100 Fuel Types There are a variety of fuels available in RdSAPMost heating systems are designed to run on a specific fuel, so make sure you know the fuel type of the heating device.

101 Mains GasMains gas is piped to individual properties and one of the cheapest and cleanest fuels widely available in the UKYou musts state whether mains gas is present or not in an EPC. If a property has a gas meter or gas burning appliance within the property it has mains gas.A closed of gas pipe does not mean mains gas is availableIf mains gas is available in the local area, but has not been piped to the specific property, then mains gas is not available

102 Heating OilHeating oil is commonly used in areas which do not have a mains gas supplyThe oil is stored in a large tank on site and must be delivered in bulkOil tanks are usually metal or moulded plasticOil boilers are usually larger and more heavy duty than gas boilersIt is possible to get, regular, combi and condensing oil boilersThe boiler pictured is a regular oil boiler.

105 Oil TankThis is typically the type of tank you will find with heating oil. They are usually plastic. But can be sunk into the ground meaning you will only see the filling cap.

106 Bulk LPG LPG – Liquid Petroleum GasThis is an alternative to oil in areas which are not on mains gasBoilers are manufactured to run on LPG specifically.Several boiler manufacturers have a mains gas and LPG version of some of their boilers, so it is important to confirm whether or not it is LPGLPG is stored in a tank and will be delivered in bulk to the propertyLiquid Petroleum GasCommon in areas with no mains gasVery expensiveManufactured product to associated CO2 emissions are highMany manufacturers produce LPG boilers equivalent to mains gas models

107 LPG - BottledSome properties may use LPG cylinders rather than a bulk tank.LPG is a manufactured fuel, which means both bottled and bulk LPG have a much higher costs than most other fuel types.The manufacture process also increases the carbon emissions.This results in a poor EPC rating, usually 2 or 3 bands lower than a property with a mains gas equivalent boiler.It may be worth advising your client of this during the survey

108 Underground Bulk LPGSome properties may have their LPG tank buried in their garden.You will only be able to see a man hole cover.

109 Electricity There are a few electricity meter options in RdSAP SingleDualUnknown24 hour (Scotland Only)

110 Electricity Single meterThis indicates the property is on a standard tariffthe meter should only show one readingA few examples of single meters are shown below

111 Electricity Dual meter This means a property has two electricity ratesa standard rate, charged for electricity used during the dayan off peak rate, charged for electricity used over night and electric storage systems have been developed to take advantage of thisThis type of electricity tariff is also known as Economy 7, this is because the tariff applies to 7 hours overnight

112 ElectricityA dual tariff can be identified by the meter present at the property.Originally properties with a dual tariff would have two electricity meters, one for each tariffMore modern meters tend to have both readings in one meter, either a mechanical meter with two readouts visible, or a digital meter with a button to switch between the two readingsSome modern meters have ‘single phase’ printed on them, this does not indicate the tariff, as most dwellings have a single phase supply.

113 Electricity 24 Hour Meter Unknown meterThe 24-hour tariff option, which is almost exclusive to properties in Scotland, does have some exceptions for England.Specifically, there are properties in Northumbria that are supplied by Scottish Power and use the 24-hour tariffIt is highly unlikely the 24 hour tariff will be found anywhere else in England, Wales or Northern IrelandUnknown meterthis option should be used if it is not possible to access the meter.The software will assume a single meter, unless the main heating or water heating require an off-peak tariff (such as storage heaters)

114 Solid fuel Coal Anthracite Smokeless fuelcan be used in open and closed room heaterscannot be used in Smoke Control ZonesAnthraciteused as a replacement for coal in Smoke Control ZonesSupplied in grains or nuts, smaller than coalCan be used in solid fuel central heating boilersSmokeless fuelUsed as a replacement for coal in Smoke Control ZonesCan be used in open and closed room heatersMuch more expensive than coalIs a manufactured fuel, the coals are usually a uniform shape

115 Solid fuel Wood also known as biomass Comes in various formsWood logsWood chipsWood pelletsWhen biomass fuel is combusted is releases carbon dioxide, but no more than it absorbs whilst the tree grows. Biomass is therefore considered to be carbon neutralWood pellets and wood chips can be used in biomass boilersWood logs are used in open and closed room heaters

117 Biomass and BiofuelBiomass can be burnt directly to provide heat in buildings. Wood from forests, urban tree pruning, farmed coppices or farm and factory waste, is the most common fuel and nowadays is used commercially in the form of wood chips or pellets, although traditional logs are also used.Biomass boilers can be designed to burn smokeless fuel to comply with the Clean Air Acts.Boilers can be fed automatically by screw drives from fuel hoppers. This typically involves daily addition of bagged fuel to the hopper. Electric firing and automatic de-ashing are also available.Biomass boilers replace conventional fossil fuel boilers and come with the automated features mentioned above. Fuels other than wood, such as straw can also be used.

118 Biomass and BiofuelBiomass is normally considered a carbon neutral fuel, as the carbon dioxide emitted on burning has been (relatively) recently absorbed from the atmosphere by photosynthesis and no fossil fuel is involved.The wood is seen as a by-product of other industries and the small quantity of energy for drying, sawing, pelleting and delivery are discounted.Biomass from coppicing is likely to have some external energy inputs, for fertiliser, cutting, drying etc. and these may need to be considered in the future.

121 Boiler ProgrammerA programmer determines the time the heating is switched on and offProgrammers can be mechanical or digitalThey usually control the space and water heating

122 Room ThermostatA room thermostat measures the air temperature, if the set temperature has been reached it will feed back to the boiler to switch offA room thermostat must be separate to the boiler, they are usually wall mounted.

123 Room ThermostatA thermostat situated on a boiler is most likely there to control the temperature of the water in the system, rather the actual room temperatureIf a wireless thermostat is fitted then the thermostat may not be in a fixed position, but the transmitter should be located near the boiler.Combined programmer and room thermostats are also quite common now, the time and temperature will be shown on the display.

124 Not a room thermostat These are examples of Frost statsA frost stat can be set at a low temperatureThey are designed to turn the boiler on when the temperature gets low to prevent the pipes freezing.They are usually fitted near a boiler when it is located in or garage or outbuilding where the temperature can drop very low

125 Thermostatic Radiator Valves (TRV’s)TRVs sense the temperature of individual radiators, the sensitivity can be adjusted by turning the valveThey will cut off the flow into the radiator if it has got up to temperatureRadiator cut off valves are not classed as TRVs as they are only used to manually shut off a radiator

126 Bypass If a system has a programmer and TRVs it must have a bypass.A bypass is a radiator with no TRV.If all other radiators TRVs are turned down there is an outlet (bypass) for the boiler

127 Boiler Energy ManagerThis device works in conjunction with a programmer and TRVs to adjust the output of a boiler based on a variety of external data includingWeather compensator – this adjusts the output of the boiler based on internal or external temperatures. Sensors are usually located around the building for this type of systemNet setback – maintains a low temperature overnight to reduce the warm up time for the system in the morning

128 Zone controlA property can be split into zones which can have independent control of the heatingEach zone should have it’s own room thermostatThere may be one programmer with the facility to independently control each zoneThis type of system is usually found in larger properties

129 Boiler InterlockThis is not a physical device but an arrangement of the system controls so as to ensure that the boiler does not fire when there is no demand for heat.In a system with a combi boiler it can be achieved by fitting a room thermostat.In a system with a regular boiler it can be achieved by correct wiring interconnections between the room thermostat, cylinder thermostat, and motorised valve(s).It may also be achieved by a suitable boiler energy manager.In systems without an interlock the boiler is kept cycling even though no water is being circulated through the main radiators or the hot water cylinder.

131 Other Heating ControlsStorage heaters have either manual or automatic charge control.Most will have manual controls on the top of the heater.Some may have automatic control, this means they have sensors which monitor the difference in temperature in the room and the heater. The temperature is the automatically adjusted to the correct level.Appliance thermostats appear on electric heaters and other room heaters, they control the temperature for the individual appliance

132 Questions Name the most common types of gas boiler? How do they work?Which are most efficient?How would you identify them during a survey for an EPC?How are central heating systems controlled?What are the main components and how do they contribute to the efficient operation of the system they control?